SignupUser via URL API error (ExceededSessionTypeHostLimit)

[maximbai1]

Hello, everyone.
I'm trying to signup a user using URL API. My request is as follows:

https://<mydomain>.webex.com/<mydomain>/p.php?AT=SU&FN=testfname&LN=testlname&EM=user@google.com&PW=SomePassword!1&PID=<myPartnerID>&WID=someuserwid

The response I get is

<SignUp><Status>FAIL</Status><Reason>ExceededSessionTypeHostLimit</Reason></SignUp>

The explanation in the documentation is extremely brief and does not help to solve the problem.
Some time before this request worked fine, but now it fails for some reason.
Any suggestions?

[nmorrow]

Hello,

     Some WebEx sites may have a limited number of available licenses for host accounts. The error response indicates that you are already at that limit. Your WebEx account manager can assist with adding more licenses if needed.